The present disclosure relates generally to backlights for displays, and more particularly to light emitting diode based backlights.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Liquid crystal displays (LCDs) are commonly used as screens or displays for a wide variety of electronic devices, including portable and desktop computers, televisions, and handheld devices, such as cellular telephones, personal data assistants, and media players. Traditionally, LCDs have employed cold cathode fluorescent light (CCFL) light sources as backlights. However, advances in light emitting diode (LED) technology, such as improvements in brightness, energy efficiency, color range, life expectancy, durability, robustness, and continual reductions in cost, have made LED backlights a popular choice for replacing CCFL light sources. However, while a single CCFL can light an entire display; multiple LEDs are typically used to light comparable displays.
Numerous white LEDs may be employed within a backlight. Depending on manufacturing precision, the light produced by the individual white LEDs may have a broad color or chromaticity distribution, for example, ranging from a blue tint tint to a yellow tint or from a green tint to a purple tint. During manufacturing, the LEDs may be classified into bins with each bin representing a small range of chromaticity values emitted by the LEDs. To reduce color variation within a backlight, LEDs from similar bins may be mounted within a backlight. The selected bins may encompass the desired color, or target white point, of the backlight.
High quality displays may desire high color uniformity throughout the display, with only small deviations from the target white point. However, it may be costly to utilize LEDs from only one bin or from a small range of bins. Further, the white point of the LEDs may change over time and/or with temperature, resulting in deviations from the target white point.